The Greek word translated “desire” is epithumia, which literally means over-heated desire or lust. Desire in and of itself is not evil. God has desires. But God’s desires are under His control, while ours are not. We desire over-much and we become over-heated in wanting, so we take shortcuts and we overeat and we overindulge and we over-do-it in getting things, but our over-desire cannot be fully satisfied because it wants over-much. James is graphic in describing this over-desire as a womb conceiving and giving birth to sin. And sin, as a growing thing that when mature “brings forth death.”
God has given us “every good gift” (James 1:17), yet we desire the gift over the Giver. However, when we receive the “word of truth” (James 1:18), which is the gospel, we are born again of the Spirit of God. And His Spirit gives us His desires and grants us self-control over our “over-desires.” Being born again, we begin to desire the Giver more than the gift.